Stellar Spectra Flashcard

Front

What is an emission spectrum?

Back

An emission spectrum is a spectrum of the electromagnetic radiation emitted by a source, showing the wavelengths of light emitted by atoms or molecules when they transition from a higher energy state to a lower energy state.

Front

What is an absorption spectrum?

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An absorption spectrum is a spectrum that shows the wavelengths of light absorbed by a substance, indicating the specific energies that correspond to the transitions of electrons in atoms or molecules.

Front

How can scientists identify unknown gases using spectra?

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Scientists can identify unknown gases by comparing the observed emission or absorption spectra of the gas with known spectra of elements, looking for matching wavelengths.

Front

What color results from mixing green and blue light?

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Cyan is produced by mixing green (G) and blue (B) light.

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What is the significance of spectral lines in identifying elements?

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Spectral lines are unique to each element and serve as fingerprints, allowing scientists to identify the presence of specific elements in a sample based on the wavelengths of light emitted or absorbed.

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What is the role of temperature in the emission spectrum of a gas?

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The temperature of a gas affects the energy levels of its atoms, influencing the wavelengths of light emitted when electrons transition between energy levels.

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What is the difference between continuous and line spectra?

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Continuous spectra show a full range of wavelengths without gaps, while line spectra consist of discrete lines corresponding to specific wavelengths emitted or absorbed by elements.

Front

What element is identified by the emission spectrum with lines at 656 nm, 486 nm, and 434 nm?

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These lines correspond to the emission spectrum of Hydrogen.

Front

What is the principle behind the use of spectroscopy in astronomy?

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Spectroscopy allows astronomers to analyze the light from stars and galaxies, revealing their composition, temperature, density, and motion based on the observed spectra.

Front

What is the relationship between wavelength and energy of light?

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The energy of light is inversely proportional to its wavelength; shorter wavelengths have higher energy, while longer wavelengths have lower energy.